textproduct: Albany

SYNOPSIS

A strong clipper system moves through today across eastern New York and western New England. Temperatures and terrain will influence rain/snow amounts today. Lake effect snow showers and upslope snow with gusty winds behind the system for Thursday. Cold, well below normal temperatures continue into next week.

SHORT TERM /THROUGH THURSDAY NIGHT/

Key Messages:

- Widespread accumulating precipitation today with a strong clipper system moving through.

- Winter Weather Advisories have been upgraded to Winter Storm Warnings in portions of southern Vermont for high elevation snowfall amounts greater than 7 inches.

- Snowfall amounts greater than 7 inches for north of I-90 in portions of the southern Adirondacks today will contribute to difficult traveling conditions this afternoon and evening.

Discussion:

As of 2:30 AM EST...Latest surface observations and low-level water vapor satellite imagery shows the strong clipper system moving into the Great Lakes region that will continue to head north and east today. This system brings onset precipitation type to be all snow as colder air at the surface continues to contribute temperatures being below freezing this morning between 5 AM and 8 AM. The current forecast supports temperatures across the western Adirondacks, southern Greens, and portions of the eastern Catskills to remain below freezing for an all snow event. Temperatures across valley locations will need to be monitored closely this afternoon as snow mixes with rain before transitioning to all rain for the late afternoon hours. Outside of high terrain locations, the current forecast supports light rain/snowfall amounts. Snowfall amounts range between a coating to 2 inches. Rainfall amounts range between a tenth to a quarter.

For southern Vermont, snowfall amounts in the valleys range between 1 to 4 inches. Latest forecast guidance models are supporting snowfall totals above 1000 feet to range between 6 and 12 inches. As these new higher totals support warning criteria, the Winter Weather Advisory for Bennington and western Windham counties have been upgraded to Winter Storm Warnings. But, this is will highly elevation dependent as elevations below 1000 feet are forecasted in that 1 to 4 inch range due to temperatures staying more mild for a more rain/snow mix. For the eastern Catskills, most locations range between 2 to 5 inches. A Winter Weather Advisory continues for western Ulster county where localized amounts range between 4 and 6 inches.

For the southern Adirondacks and western Mohawk Valley, latest NBM and high resolution model guidances continue to support the highest snowfall totals north of the New York State Thruway (I-90). A narrow band of higher totals to the north comes from where the moderate to heavy bands of snowfall set up for today as snowfall rates could range between 1 to 2 inches per hour. For the western Mohawk Valley, temperatures rise above freezing during the afternoon hours for that transition over from snow to rain. Snowfall totals range on the lower end between 1 to 3 inches. Winter Storm Warnings and Winter Weather Advisories continue for these locations from this morning through tonight.

Bottom line up front, the terrain and temperatures are going to be the biggest influence with this clipper system for snowfall totals today. Be prepared for winter weather impacts this afternoon and evening in high terrain locations. By tonight and Thursday morning, the clipper system heads north and east. Behind this system, lake effect snow showers and upslope snow return for Thursday as well as gusty winds. Additional snowfall amounts are currently forecasted to be between 0.5 inches and 3 inches.

Latest probabilities from the National Blend of Models (NBM) data for winds gusting greater than 40 mph is between 50 and 80 percent for the northern Berkshires. Probabilities across the highest terrain locations in the eastern Catskills have increased to between 50 and 60 percent for greater than 40 mph wind gusts. Elsewhere across eastern New York and western New England, probabilities are less than 30 percent. The higher side of those probabilities are for the eastern slopes of the Berkshires as the terrain will play a part in if winds exceed 40 mph. Nevertheless, winds will be gusty Thursday afternoon into Thursday night as the clipper system heads further north and east with winds gusting between 25 and 35 mph.

LONG TERM /FRIDAY THROUGH TUESDAY/

Key Message:

- A colder airmass returns overhead Sunday into early next week with well below normal temperatures continuing across eastern New York and western New England.

Discussion:

Lake effect snow showers taper off Thursday night and Friday with low chances remaining for light snow showers Friday across Herkimer county. Most locations stay dry and cold with highs in the 20s and low 30s. Winds decrease Friday morning with gusts between 5 and 15 mph. Our weather pattern into the weekend remains active as ensemble forecast model guidances are supporting an upper level trough to dig southward and move through eastern New York and western New England bringing low to medium chances for snow showers Saturday and Sunday. Associated with this trough is much colder air behind it with an arctic front moving through Sunday. This contributes to the potential for bitterly cold temperatures Monday morning with lows ranging five below to the single digits. Dry conditions are favored to briefly return Monday as the upper level trough heads east and upper level ridging moves in. Highs Monday range in the teens and 20s. These below normal temperatures stick around for Tuesday with cold lows in the single digits and highs in the 20s.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

Through 12z Thursday...Snow onset delayed a few hours from previous forecast, now expected between 13z-15z at KGFL and 14z-17z and will continue mention TEMPO for IFR vsby and MVFR cigs. Prevailing snow then anticipated after 15z at KGFL and 17z at KALB, with conditions deteriorating to IFR. The precip onset will take longer at KPOU/KPSF, so will mention TEMPOs early-mid afternoon for IFR vsby at KPSF and MVFR vsby at KPOU. Steadier precip should move in across these sites between 19z-20z, with temperatures warming enough for a rain/snow mix at KPOU with prevailing snow at KPSF. Conditions will deteriorate to IFR at KPSF but should mainly remain MVFR at KPOU. Some rain could even mix in at KALB by around 20z. Steady precip should end at KALB/KPOU by 00z-01z Thu, but should linger at KGFL/KPSF into the evening with conditions likely to remain IFR at KGFL/KPSF with MVFR at KALB/KPOU.

As a southerly jet of 40-45 kt at 2000 ft AGL moves overhead this morning into the afternoon, will mention low level wind shear at all sites with surface winds generally 12 kt or less. The LLWS will dissipate during the evening at the jet shift east of the area. Surface winds will be southerly around 7-12 kt with occasional gusts around 20 kt. Winds will shift to the west after 06z Thu at 10-15 kt with gusts of 25 kt at KALB/KPSF.

Outlook...

Thursday Night: Low Operational Impact. Breezy. Slight Chance of SHSN. Friday: Low Operational Impact. Breezy. NO SIG WX. Friday Night: Low Operational Impact. Slight Chance of SHSN. Saturday: Moderate Operational Impact. Chance of SHSN. Saturday Night: Moderate Operational Impact. Chance of SHSN. Sunday: Moderate Operational Impact. Breezy. Chance of SHSN.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...Winter Storm Warning until 7 AM EST Thursday for NYZ032-033- 082. Winter Weather Advisory until 1 AM EST Thursday for NYZ038- 041>043-063-083. MA...None. VT...Winter Storm Warning until 1 AM EST Thursday for VTZ013-014.